package com.itheima.reggie.filter;

import com.alibaba.fastjson.JSON;
import com.itheima.reggie.common.BaseContext;
import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;



@Slf4j
@WebFilter(filterName = "loginCheckFilter",urlPatterns = "/*")
public class LoginCheckFilter implements Filter {
    //路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();
    @Autowired
    private RedisTemplate redisTemplate;
    /**
     * A. 获取本次请求的URI
     *
     * B. 判断本次请求, 是否需要登录, 才可以访问
     *
     * C. 如果不需要，则直接放行
     *
     * D. 判断登录状态，如果已登录，则直接放行
     *
     * E. 如果未登录, 则返回未登录结果
     * @param servletRequest
     * @param servletResponse
     * @param filterChain
     * @throws IOException
     * @throws ServletException
     */
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
//获取本次请求的URI
        HttpServletRequest request = (HttpServletRequest)servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        String requestURI = request.getRequestURI();
        //定义不需要处理的请求路径
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/common/**",
                "/user/sendMsg",
                "/user/login"
        };
//        判断本次请求, 是否需要登录, 才可以访问
       boolean check = check(urls, requestURI);
       // 如果不需要，则直接放行
       if (check){
           filterChain.doFilter(request,response);
           return;
       }
//        判断登录状态，如果已登录，则直接放行
        if (request.getSession().getAttribute("employee")!= null){
            Long id = (Long) request.getSession().getAttribute("employee");
            BaseContext.setCurrentId(id);
            filterChain.doFilter(request,response);
            return;
        }

        if (redisTemplate.opsForValue().get("user")!=null){
            Long userId = (Long) redisTemplate.opsForValue().get("user");
            BaseContext.setCurrentId(userId);
            filterChain.doFilter(request,response);
            return;
        }
//        如果未登录, 则返回未登录结果
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;
    }

    private boolean check(String[] urls, String requestURI) {
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match){
                return true;
            }
        }
        return false;
    }
}
